Car retarder for railroads



Jan. 5, 193 2. c. w. PRESCOTT CAR RETARDER FOR RAILROADS Filed Dec. 9, 1929 m 8 m2. GM km mvz-zmo L BY 6. w %WAYTORNEY Patented Jan. 5, 1932 I UNITED. STATES PATENT OFFICE CHARLES W. PRESCOTT, F MILL HILL, ENGLAND, ASSIGNOR 1 SIGNAL COMPANY, OF ROCHESTER,

'10 GENERAL RAILWAY NEIV YORK GAR RETARDER FOR RI'KILROADS Application filed December 9, 1929. Serial No. 412,757.

This invention relates in general to car retarde'rs, and has more'particular reference to a'car'retarder of the track brake type in provided for effectually prewhich means are venting car wheels from climbing out from 7, between the retarderbrake shoes.

The present invention is an improvement in theinventi'on disclosed in the Howe application 244,259 filed January 3, .1928. 7

In the use of car retarders of the track brake type,-ithas been found that there isa tendency for the car wheels to climb up out of the retarder, upon. the degree of retardation becoming excessive. This is of course, objectionable in that retardation is prevented and derailmentof a car "or cars and breakage of various parts is likely.

'1 With the above considerations'in. mind, it is proposed in accordance with this invention to provide a car retarder, of the type in question, with meanslfor preventing'car wheels from climbing out from between the retarder shoes.

' More specifically, it is proposed to provide a structure including two spaced pivoted levers arranged to control the degree of retardation by varying the distance between their pivot points, with means 'for automatically moving oneof'the pivot points relatively to the'other upon a car wheel starting to climb out, whereby to decrease the degree of retardation to the maximum permissible and still have the retarder' operative to retard the wheels.

Further objects, purposes and characteristic features of the present invention will appear as the description-progresses, reference being made to the accompanying drawings, showing,1solely by way of. illustration, and in no manner. in a limiting sense, several embodiments which the invention can assume. In the drawings z- I Fig. 1 is a'transverse sectional view, with parts shown in elevation, of one form of the invention.

ig. 2 is a transverse sectional view, with parts shownin elevation, of a modified form parts shown in elevation, of another modified form of the invention.

Referring to the drawings, and first to the form of invention shown in Fig. 1, there is here shown a tie 1, constituted preferably by a steel I beam, supported on any suitable bed 2, such as a wooden tie. Carried on ties 1, of which there is a series as would appear from a plan view, such as in the Howe application above identified, are running rails 3, of the special form shown. Each rail 3 comprises a usual head portion, for receiving the tread of a car wheel, and a down wardly projecting web portion 4, which is vertically slidable between fixed side supports 5, each web 4 being operably connected to an angle arm 6, carried on a fixed pivot 7, the web 4 being pivoted as at 8 to the angle arm 6. The other end of each angle arm 6 is pivoted, as at 9, to an arm 10 carried on a pivot pin 11.

Positioned at each side of each rail 3, is a brake shoe 12,

carried in any usual or desired manner by a brake beam 13, each brake beam having an aperture 14 therein,,for receiving the upper end of a pivoted arm 15, pivoted as at 16 and 11.

Positioned between the lower ends of the arms at each side of each running rail 3, is a compression spring 17 preferably pretensioned, which constantly operates to bias the lower ends of each pair of arms 15 outwardly away from each other. The brake beams 13 are horizontally slidably mounted relatively to the rails 3, in a direction transverse to such rails, whereby the springs 17 Operate to urge the brake shoes 12 inwardly toward the track rails, and to resist any tendency to separate the brake shoes 12. In one of the brake beams 13 of each pair of brake beams associated with each rail 3, is a centering spring 18, arranged to center the brake shoes 12 at an equal distance from each side of the rail 3, it being clear that otherwise these brake shoes might assume an unoentered position without in any manner affecting the tension of the retarding spring 17.

Controlled by any usual or desired means, such, for example, as a motor. asshown in the Howe application, is a rod 19, slidable transversely of the rails 3 and positionable in any one ofseveral positions, and held in such positions by means of crank and lever mecha nism 20, 21, etc, as for example, in the Howe application above identified. Fastened to rod 19 are bloc is 22, one for each running rail, in which are mounted the pivot pins 16, whereby movement of rod 19 results in bodily movingthe pivot pins 16. Theother pivot pin '11 for each running rail, is carried by the arm 10 connected to the angle lever '6, and is mounted to be movable thereby, in a horizontal direction toward and been fixed instead of movable. 'ot pins so positioned, and'held, by rod 19 and tion, for example, and holding it away from rail 3, according as rail 3 is depressed and raised in its guides 5. A consideration of thestructure just de scribed, makes it clear that the resistance to separating brake shoes 12 increases the pivot pins16 and liars brought closer together, and that 7 hese pivot pins can be brought-closer togetherby moving rod 19 to the left as viewed in Fi 1, if pivot pin11 beheldagainst-movement. This pivot pin 11, however, as just described, isnot held in fixed position, but is controlled by movement of its running'rail 3. 7

Assumethe parts shown in. Fig. 1 to be po :sitioned forthe lowest degree of retardation.

On moving rod 19. to the left to its first posi in such position, the force exerted' on pivot pin 16, by rod 19,} is transmitted through the lower end of the right. hand arm 15 then through spring and through the companion arm 15, to bodily move pivot pin 11'tothe left, whereby spring 17 is not additionally tensioned by movement oiithe rod 19 and the degree of retardation is not at all changed with the track rail 3 unoccupied. V

On occupancy-of track rail 3, however, this rail is depressed to bring its head against the guide members 5, and thereby operates through angle lever 6 to draw pivot pin 11inwardly, toward the track rail and hence to Ward pivot pin 16'. As a result, the pivot pins 11 and 16 are brought together, on occupancy of the track rail 3, to the position they Would have at once assumed, had pivot pin 11 WVith the piV- the weight of the ear, the degree of retardation exerted by the brake shoes 12 isdepend ent on the position of the pivot pin 16, or, in other words, is dependent on the position to which rod 19 hasbeen moved and held.

' If now, for any reason, a car wheel should startto climb out from between the retarder shoes 12, the weight-on rail 3 is immediately relieved, with the-result that spring 17 moves pivot pin 11 outwardly, a'way'from the: track rail, so as to increase the distance betweenthe pivot pins 11 and 16,and' so reduce thedegree of retardation to the maximum which is permissibleand'stillnot cause the wheel to climb out.

In this manner a means is provided which automatically operates to sufficiently reduce the degree of retardation only suflicientlyto prevent any climbing out of the car wheels, and thus prevent derailment, etc.

The necessary amount of movementof the rail 3 for effecting thisfop eration is very slight, and has been exaggerated in the drawing for the purpose of illustration. The movements of pivot pin 11 and track rail 3 are limited, as by a stop pin 23 or the like.

The arrangement of parts for each track rail 3 is identical, and likewise for a double track road the arrangement of Fig. 1 would simply be duplicated.

The positions of thestop pins 23, can. of course be varied in accordance with requirements, as can also be varied'the lever ratios of the various levers', 6', 10, 15, etc. Likewise the tensions of the springs17 and 18 can be varied as required in practice under various conditions. i

' Theretarding spring- 17 is preferably of such a strength, and is so tensioned, that with the pivot pin track rail 3to'the greatest possible extent, corresponding to the maximum degree of 7 retardation, the lightest car to be retarded is heavy enough to fullydepress rail 3 until its head contactswith its guidememb'ers -5. Under these conditions,the degree of retardation exerted on any car, is independent of the Weight ofthe car, and is dependentupon, the position to whichrod .19 has been moved and held. I

On consideration, it is clear that the retarder spring 17 can be made stronger, so that it is possible to move the pivot point16 inwardly toward the running rail a sufiicient distance to prevent 31031 of a giveniweight, one of the lighter cars to be handled, for example, from fully depressingra-il 3. Under such conditions, the maximum retardation ossible-without'climbing out, is exerted on such a car, this retardation being determined by. the weight of the car itself, and beingexerted regardless of whether or not the pivot pin 16 be moved further inwardly toward the track rail.

. It is thus seen that by ad usting the tension ;-The running rails 3 are flexible enoughto 1 permit-suflicient raising, upon a carfwheel starting to climb out of the retarder, 'to permit the required reduction of retardation for preventing the wheel from climbing out. As

16. moved inwardly toward its V greater movement of the track rail than is and rail 3 of Fig.

-a jointed or articulated rail so'as permitted by the flexibility of thecontinuous steel rail, is necessary or desirable, to provide flexibility in a vertical plane suificient to reduce thev degree of retardation enough to prevent climbing out of the car wheels. It is possible, with. particular lever ratios of the various levers involved, that the flexibility of a continuous steel rail might not be sufficient to sufliciently reduce the, degree of retardation under all conditions. In such cases the flexible rail referred to would be used in place of acontinuous rail..-

-eferring now a, to. Fig. 2, there is here shown a modified form of the invention, .in which the running rail 3 is not. movable, but theangle lever 6 is actuated byan auxiliary railf24', positioned along-the side-of the running-rail 3 in position to receive the weight, or part of the weight on a' car wheel, through the flangeof such wheel. I V, In the formof Fig. 2,'the' operation is-substantiallyv the same as described above in connection with Fig. I.'.' Upon a car 0ccupying the running rail 3 the wheel flanges bear on rail 24 to thereby bring pivot pin 1].. inwardly toward rail 3 depress this rail and to thereby maintain. the .predetermined degree of retardationcdesired, unless the car wheel tends to climb out, atwhich time rail 24 raises to therebyflmore widely separate pivot :pins llzand 16, to sufficiently reduce the degree-" of retardation to prevent any climbingout I I ..Referring now to Fig. 3, there is 1 here shown another-embodiment of applicants invention, in which the running rail 3 is carriedyon heavy'coil springs 'received in sockets in ties 26, .there being a spider frame 27 connecting'rail -3 to1one end'of angle lever 6. In this form of the invention, the'track rail'3 on a car occupying the retarder, is pressed down into contact with the tie 26to thereby operate angle lever 6. and associated parts, as described 'inconnectionwith the first twoiorms of the invention.

In the-form of Figure 3, the joints 8 and 9 are knife edgefbearing joints, as shown, instead of pin joints as in Figs. 1 and 2. In the formsshown in Figs. 2 and 3, usual running rails 3 can be employed, the. auxiliary rail 24 ofFig; 2, being inherently flexible. enough for proper operation, or being articulated in a vertical plane to make it more flexible, ifdesired, in the manner described in. oonnectionwith rails 3 of Fig. 1, 3, they being made more flexible by 'IOrmingYthem of .i a plurality of to permit 1 short articulated sections, if desired, all as described in connection with rail 3 of Fig. 1.

The 'proportions,'sizes, and shapes of the various members involved in the above described structure, can be cordance with'the attendant circumstances, to fit them in practice for varying conditions ofoperation, without departing from the present invention.

The above rather specific description of several devices embodying this invention, is given solely by way of illustration, and is notintended,-in an manner whatsoever, in a limiting sense. bviously, this invention can assume many different physical forms,

and is susceptible of various modifications, and all such forms and modifications areintended to be included in this invention, as come within the scope of the appended claims.

Having claim zj 1. In a car retarder, in combination, a running rail, a retarder shoe adjacent each side of the rail and movable away from the rail against biasing means urging the shoes inwardly toward the rail, manually controllable adjusting means for varying the strength of the biasing effort, and means for reducing the strength of the biasing eflort in proportion as the rail is relieved of a load.

2. In a car retarder, in combination, a runningrail, a retarder shoe adjacent each side of the rail and movable away from the rail against biasing inwardly toward the rail, manually controllable adjusting varying the described my invention, I now means for strength of the biasing effort, when a load is applied to the rail, and means for reducing widely varied in 210- 5 means urging the shoes the strength of the biasing effort in proportion .as the rail is relieved of its load.

3. In a car retarder, in combination, a running rail, ajretarder shoe adjacent each side of the railand movable away from the rail against biasing means urging the shoes inwardly toward the r-ail, manually controllab'le adjusting means for varying the strength of the biasing effort, and means operatively interconnecting the rail and the shoes for reducing the strength of the biasing effort, in proportion as the rail is relieved of a load. In a car. retarder, in combination, a retarder shoe adjacent each side of a running rail, a pivoted arm carrying each slice, biasing means constantly urging the arms to rock on their pivots to bias the shoes toward the rail, manually controllable adjusting means for moving one of the arm pivots for varying the distance between the two arm pivots to thereby vary the strength of the bias on the shoes, and means causing the other arm pivot to be bodily moved according as a load is applied to, and removed from, the rail.

5. In a car retarder, in combination, a retarder shoe adjacent each side of a running rail, a pivoted arm carrying each shoe, biasfor movingone of the arm pivots for vary- 1 ing'the distance between the two arm pivots to thereby vary the strength ofthe bias: on the shoes, and means causing the other arm pivot to' be bodily movedtoward, or away from, the manually controllable arm pivot, accordingas a load isapplied to,or removed from, the rail. 1 6; In a car retarder, in combination, a run-i ning rail, a'pivot at each side of the rail and movable toward andaway from, therail, an arm carried by each pivot, a brake shoe" on each arm and adjacent the rail, biasing, means acting on thearm to bias the shoes toward the rail with a force varying with the distance between the pivots, manually con trolled means. for-moving oneof said pivots, and automatic means for moving the; other pivot'in accordance withthe load on therail.

7. In a car retarder, incombination, a running rail mounted to move vertically between fixed guides, a. pivot at each side of the'rail and movable toward and away from, the rail, an: arm carried by each pivot, a brake 7' shoe on each arm andadjacent the rail, biasing means acting on the arm to bias thesl oes toward therail with a force varying with the distance between the pivots, manually controlled means'for moving one of said pivots,

' and automatic means for moving the other pivot in accordance with the load on the rail. 8. In a car retarder, in combination, armining rail mounted in fixed position, and a vertically movable auxiliary rail adjacent the running'rail'to receive the flange of; a

on each arm and adjacent therail,

wheel on the'running rail, a pivot at each side of the'rail and'movable toward and, away from, the rail, an arm carried by each-pivot, a brake shoe on each arm and adjacent the .rail, biasing means acting on. the arms to bias the shoes toward the rail with aif orce varying with the distance between" the pivots, manually controlled means for moving one of said pivots, and automatic means for moving the other'pivot in accordance with the load on the'rail. f v 9. In a car retarder, in combination, a

runningrail, a pivot at each side of the rail 7 and movable toward andaway from, the rail, an arm carried by each pivot, a brake shoe biasing means acting on the arms to bias the shoes toward the rail with a force varying with the distance between the pivots,- manually controllable means for moving one of the pivots, a lever connection between the-other pivot and the rail, and'meansinounting the rail for vertical movement,wherebyvertical movementof the railmoves said other pivot to'thereby" automatically vary rthe biasing force. F r

' -10: lira car reta'rdenin 'combination Qa running rail, .a retarder' shoe; adjacent each side of the rail and movable-away from. the rail against biasing means; urging the shoes inwardly toward the raihand :means I operatively interconnecting the rail and'the shoes for reducing. thestrength of the biasing "effort, in proportion astherail is relieved of 11. Ina car retarder, inicombination, a retarder shoe adjacent each side of a running rail, a pivoted arm carrying each shoe, biasing means constantly urging the -arms to rock on-their pivots-to bias the shoes toward the rail, and operative connecting means between one of the arm pivots and a loadon the rail, including means slidably supporting the rail if or vertical movement, and a connection;betweenv the: rail and the arm pivot, whereby to cause the one arm pivot to be bodily moved 'according as a load is applied to, and removed from, the raiL- 1 '-1 2.'In a carretarder, incombination, a retarder shoe adjacent each side of a running rail, a pivoted arm carrying each shoe, biasing means constantly urging the arms to rock '13. ln -a car retarder,"in combination, a

retarder shoe adjacent each side of'a runningrrail, a pivoted arm carryingiea'ch shoe, biasingmeans constantly urging the arms to rock on their pivots tobias theshoes toward the rail, and operative connecting means between one. of the arm pivots and a load'on the rail, including means slida-bly supporting the rail for verticalmove'ment', and apivot pinnedconnection betweenthe rail and-the arm pivot,' v whereby to cause the one 'arm PlVOtdO be bodily moved according as a load 1s applied to, and 'removedfrom, the ma.

. '14, In acar retardeiyin combination, a retarder shoe adjacentjeachxside of'a running rail, :a pivoted arm carrying each shoe, biasing means constantly urging the-arms to rock on;their pivots to bias-theshoes toward the rail, and operative connecting means between one ofthe arm: pivots and a load on the rail, including resilientmeans slidably supporting the rail for vertical movement, and a connection between the'rail' andthe a-rm'pivot, whereby to cause "the one arm 1 pivot tobe bodilymovedaccording as a load is applied to,and'r'eoved from, the rail, said connecting means including knife edge pivots. a v a 15. 'Inacarretarder, in combination, a. re:

tarder shoe adjacent each side of a running rail, a pivoted arm carrying each shoe, biasing means constantly urging the arms to rock on their pivots to bias the shoes toward the rail, a member slidably mountedadjacent the rail to receive at least part of the load of a wheel on the rail, and connecting means between said member and one of the arm pivots, whereby to cause the one arm pivot to move as a wheel passes over the rail.

In testimony whereof I affix m signature.

CHARLES W. PREYSCOTT. 

